1. Field of the Invention
The present invention relates to connectors for communication wires and cables, and particularly to a communication jack construction suitable for high frequency information transmission applications.
2. Discussion of the Known Art
A compact communications jack connector is disclosed in U.S. Pat. No. 5,096,442 (Mar. 17, 1992). The known connector is formed from a unitary lead frame in which eight flat, elongated conductive elements connect spring jackwire terminals at one end of the frame with corresponding wire connection terminals at the other end of the frame. The wire connection terminals are insulation displacement connectors (IDCs) of the "slotted-beam" type. For example, see U.S. Pat. No. 3,027,536 (Mar. 27, 1962); U.S. Pat. No. 3,798,587 (Mar. 19, 1974) and U.S. Pat. No. 4,826,449 (May 2, 1989).
In the mentioned '442 patent, the lead frame is placed against a bottom surface of a dielectric spring block, the jackwire terminals are wrapped around a tongue-like protrusion on the block, and the elongated conductive elements are positioned flat and parallel to one another on the block bottom surface. Individual IDC terminals of the lead frame are folded onto side surfaces of the block. Slots in the IDC terminals align with corresponding wire-receiving slots formed in the block, and a cover is placed around the block including the wrapped IDC terminals. The tongue-like protrusion of the block is received in a jack frame, and the jackwire terminals are aligned so that when a connecting plug is inserted the jack frame, the jackwire terminals connect electrically with corresponding wire leads in the plug.
A communication jack made by AMP Corporation (Part. No. 557901-1) and intended for high data rate applications includes a printed wire board, jackwires that emerge from a top surface of the board and bend sharply back over the board, and sets of wire connection terminals at the sides of the board. Two separate terminal covers are each held in place by pins which pass horizontally through openings in the terminal bases. The top surface of the wire board is left exposed between the separated terminal covers. A front end of the board slides into a jack frame, and tabs on the sides of the board snap in slots in rear side walls of the jack housing. The jack housing also has a rear bottom wall that extends over the bottom surface of the wire board.
Pending U.S. patent application Ser. No. 08/668,553 filed Jun. 21, 1996, and assigned to the assignee of the present invention, relates to a device for reducing crosstalk exhibited by certain connectors. All relevant portions of the '553 application are incorporated by reference herein. The device comprises a printed wire board having several dielectric layers. Pairs of conductor paths are formed on selected layers, and a conductor path of one pair is vertically aligned and spaced from a conductor path of another pair on an adjacent layer. A given set of vertically aligned paths acts electrically as a capacitor plate that cooperates with a horizontally adjacent set of vertically aligned paths, to compensate for or reduce crosstalk exhibited by a given connector. As far as is known, the crosstalk reduction scheme of the '553 application has not been applied in a communication jack.
U.S. Pat. No. 5,186,647 (Feb. 16, 1993) shows a high frequency electrical connector similar to the mentioned U.S. Pat. No. 5,096,442; but wherein certain pairs of the parallel conductive elements cross over one another as a means for reducing crosstalk. All relevant portions of the '647 patent are incorporated by reference herein. Other arrangements for reducing crosstalk are disclosed by U.S. Pat. No. 5,432,484 (Jul. 11, 1995); U.S. Pat. No. 5,299,956 (Apr. 5, 1994); and U.S. Pat. No. 5,580,270 (Dec. 3, 1996) all relevant portions of which are incorporated herein by reference.
It is also known to construct a terminal post with a retaining portion formed of two arcuate spring members which are separated by an opening, thus resembling a "needle eye". See, for example, U.S. Pat. No. 4,206,964 (Jun. 10, 1980). See also U.S. Pat. Des. No. 345,268 (Jan. 10, 1995) showing a telecommunications terminal clip having a slotted retaining portion.
There remains a need for a durable high frequency communication jack that will minimize or compensate for crosstalk between two or more signal paths through the jack, particularly when a communication plug, which alone may tend to introduce undesirable crosstalk, is mated with the jack. The resulting plug-jack connection should nonetheless allow for high data rate transmission in a wired network, whether local or global.
The desired jack should also be easy to manufacture in high volume, and be compliant. That is, the jack should maintain its high performance characteristics notwithstanding repeated connection with and disconnection from mating plugs, and use with plugs having different numbers of wire conductors. In particular, unused jackwire terminals should not be permanently deformed when deflected by plug bodies that carry fewer wire conductors than the number of jackwire terminals in the jack. With respect to manufacturing steps, a communication jack that uses minimal horizontal or side-wise tool movements during assembly, and relies primarily on vertical or straight up-and-down tool motion for its construction, is also desirable.